Machine Type Communication is a project newly introduced in a Long Term Evolution (LTE) system. The LTE is an OFDM-based system where a signaling connection setup, allocation of resources and communication over the prescribed resource is required for communication. In the LTE system, there is a specific match relationship between signaling and data, and interaction of a lot of signaling is required for the data transmission. Unlike human to human communication, e.g., lingual communication, an is Internet access and etc., the data amount of the messages required to be transmitted in MTC is low, for example, a machine simply reports a parameter (e.g., temperature, a reading of an electric meter, etc.).
For human to human communication, there is a lot of data amount to be transmitted, the proportion of signaling is low. However, for MTC, the data amount to be transmitted is low, so the proportion of signaling is low, thus resulting in signaling overload and economy problems. For example, a high proportion of signaling has to be consumed even if a message with a low data amount is transmitted.
The following situation will arise due to this problem. For example, for the data transmission between User Equipments (UEs) in MTC, the system can support data transmission of a user but can not bear signaling, that is, the system can support only a small number of users at the signaling aspect. The problem of a signaling overload as a result thereof will also influence communication efficiency.
On the other hand, both data transmission and signaling transmission will be scheduled via Physical Downlink Control Channel (PDCCH) signaling. However, PDCCH resources are limited and shared throughout a cell. Signaling resulting from MTC has a higher priority than data during scheduling. Thus, an excessive resource may be occupied and even all the PDCCH resources may be consumed by considerable signaling overheads resulting from MTC, which causes a serious consequence, for example, influencing communication of other users in the cell, restricting communication of the another user (for example, a user in an ongoing voice communication may be dropped).